Planogra



T. H. MARTEN.

ATTACHMENT FOR LIFE BOAT DAVITS. AIPPLICATION man MAR. 5, 191a.

, 3 1 9, 352 q Patented Oct. 21, 1919.

2 SHEETS-SHEET 1.

T. H. MARTEN.

ATTACHMENT FOR LIFE BOAT DAVITS.

APPLICATION FILED'MAR. 5. 1918.

1,819,352., Patented Oct. 21,1919.

2 SHEETS-SHEET 2.

THU CGIG'AKBIA PLANDGRAPH. c0., IWASHING'EON; 11.8,

THOMAS HENRY MART'EN, OF TORONTO, ONTARIO, CANADA. I

;ATTACHMENT 7 FOR LIFE-BOAT :DAYITS.

Specification of Letters Patent.

Application filed March 5, 1918. .Serial No. 220,515.

To al ljwhom it may concern:

' Be it'known that .I, ,THOMASTHENRY MAR- TEN, a subject dftheKing of Great Britain, and resident of the city of Toronto, co unty of York, .Brovince of Ontario, in the Dominion of Canada, have invented certain new and useful Improvements ;in Attachments for Life-Boat Davits, describedin the followingspeci fication and illustrated in: the accompanying drawings that lform part of the same. i l

The, principal object of this invention is to provide-improved means for minimizing the power required forfmoving ships L-bOats from their overhung or lowering position to V their inboard, or stowed position and vice ;i; the handling of ships?v boats with thetype of, davit referred to, that oneiof the xgreatest versa-and'especially for use with a davit of the type in v which the f boom swings upon a ed pivot in a verticalwplane; a It is well understood bay those skilled in diflicultiesmet with a is the excessive workroquired in raising the load in addition to that required to displaceittransversely due tothe path of travel; of;the boom headifrom whichtthe boat issuspended. Thisis more particularly the case when-the boat is being moved back from tits-overhung position.

In the operation of the ,type of davit pivoted at the foot ifpthe path of travehof the load corresponded with the path of travel of the boom head there would -be an objectionable tendency for Ithe \load to run forward when being-moved towardtheoverhung position andit is therefore desirable to effect as nearly aspossible a horizontal path of travel .for the load so that the davit and its load 'willgin all positions be in a condition of approximateequilibrium and so thatthe only workdnvolvedwilhbe that required to displace the load transversely,

The principal feature of the invention consists in ,the novel construction and arrangement of parts whereby the davit boom 7 when swinging outwardly and downwardly from the ,vertical line of support of the load is accompanied by a reactionary pull upon thetackle ropes which causes the boat to be ,heldto a more nearly horizontal path thanthat .describedby the boom head.

.Inrthe accompanying drawings Figure altis an elevational view showing ,my improved form of davit attachmentandillustrating its application to a davit and a boat, and showing :thecharacter of the path of'travel of the boat as compared with that of the davit boom head, the extreme outboard positlon being shown in dottedlines.

Fig. 2 =is-an elevational view showing the position of the members when the boom head islocated in the ivertical line of the support ofthe-load that is, in vertical alinement with thepivotsupport of the boom.

In practically all the present forms of mechanically operated davitsi in which the boom swings in a vertical plane the major portions. of the path of movement of the boat outboard] is in a downward direction due to the pivoting of theboom and the consequentdownward :movement of the boom head as it swings to an outboard or coverhung position. 1 i

It .islthe purpose of this invention to obviate this condition by efl'ecting a positive reactionary movement to draw upon the tackleropes as therboom' head swing down- Patented Oct. 21 1919.

wardly thusgcausing theboatfto travel in a i plane substantially parallel to the ship7s deck. a

In carryinglmy invention into effect I preferably utilizeasolid cast frame 1 which is rigidly securedito thedeck of the ship at the railhaving the outer upright 2 and inner post 3 connected adjacent tosthe top bythe cross piece 4 cast as part of the frame.

The crosshead barf) is secured inthe upper endiof the upright 2 and post 3 and is preferably parallelto the piece 4 which is arranged with an upward and'outward incline. V a

The boom 6is preferably bifurcated at the lower endand straddles the-frame and crosshead bar; and is {pivoted I at its "foot u Jon the pivot pin 7 whichis arrangedatthe ase of theuprightQ. a

Thor-profile of the boom ;is preferably of obtuseangular-or curved formation sorthat when the *upper portion of the boom is in an upright position the jlowerend extends diagonally acrossthe frame from the lower front to the rear upperportion, and so (that when the davit is in its-normal inboard position theboom head from which the load is suspended is inboardof the pivotal supportof the boom.

A crosshead 8 is slidably arranged on the V right 2 and post 3 3-andis arranged ima mediately below and parallel with the crosshead bar 5 and extends through the lugs. 9 on the crosshead.

A floating nut 11 is threaded on t'hespindle and held between the lugs 9 and ring arm-which lifts upwardly upon" the forms the means for effecting the travel. of the crosshead. The crosshead is formed with a bearing lug 12 on its upper and rearward endand in this lug is secured the link pin 13.

link 14 formed with a bifurcated end 15 straddling the lug 12 is secured upon the link pin 13 and the other end extends 7 through the bifurcated portion of the boom and is pivotally connected to the pin 15 secured in the forward side of the said boom. The rotation of the spindle travels the crosshead 8 upon the crosshead bar 5 and through the link14= swingsthe boom on its pivot. b I

A crank lever 16 is pivotally mounted upon a-rigid pivot pin 17 securedlin the frame adjacent to the inner side, said lever 'hav ing the long end 18 extending in an upward and inboarddire'ction I and provided with a cleat 19 at its inner end towhichjth'etackle ropeis secured. The short cranked 5 end 20 of the lever 16 extends in an outboard direction and pivotally secured to the outer end thereof is 'ashackle rod 211 The other end of the shackle rod 21 is ivotally secured to one end of the link pin 13 of the the shackle rod 21 acting as a tie permits the short endof the lever 16 to swingdowm wardly upon itspivot and allowing the long end 18 to swing upwardly and forwardly in responseto the tension in the tackleropes as the boom takes'the weight of the boat. The V upward and forward swinging movement'of' the long enact the lever is'gradually de-.

creased asthe'shackle rod approaches the position perpendicular to, the line of travel of the crosshead'until the forward 'move ment of the long end of the lever ceases as illustratedin Fig. 2. The continued forward'movement of the "crosshead"thusre verses the action ofthe lever 16 and the crossheadthen pulls upwardly upon the shackle rod 21 and short end 20 of the lever causing the, long end 18 to swing in an in board rearward direction. 1

' The path of'movement' of the lever is shown in the drawings by'a dotted. line and the limit of the outboard movement is indicated by at. The boatis suspended from the uper end of the boom by the tackle ropes 22 b and the workingpart ofthe rope is secured to the cleat 19 on the long end of the lever 16. The boom 6 is pivoted at its'foo't and normally'rests withits upper end inboard of the center of gravity and upon the operation'of the screw spindle 110 by means of the crank 23 the boom is swung outwardly. It has a considerablelifting action, that is to say, the boom head first travels in an ascendaction due to the path of off the chocks but it is found that the lifting action of the boom is suflicient for this purpose and it istherefore objectionable to have vthe. tackle ropes pull through the blocks when the davit is firstputiin'motion;

rope to the .lever 16 this objection is over comeduring the first part of the movement of therboom by the concurrent forward movement in the lever 16. This movement By attaching theworking part of the tackle is gradually decreased until'the ishacklejrod' 21 passes over the center f and a reac t onary movement in the levergl6thentakes place and as the boomcontinues to move outboard, the lever-.16 swings inboard! This reactionary movementfldraws upon the tackle ropes. and causes the boat to be carried ina substantially'horizontal path, the r reactionary movement of thelever drawing upon the ropes substantial proportion to the depressionoftheboom head in .the'

outboard portion of its travel. The path of movement of the boatis-shown by the "line m and is a 'flatarc' having its chordsubstan tially parallel tothedeckof the ship.' 'j.

Fro1n"this description andon reference J to the diagramsfit will beseenthat the boat. may be lifted clear of the chocks and carried free of the rail'of the 'shipby the ascend ing' arc, of the boom head andiis {further prevented by the reactionary means shown,

from dropping away as the boo'mjswings' outboard and downward to its maximum position with the result that a minimum of effort is requiredTtOdisplacethe load from 7 one position'to another. t l

I find the formof' davit: shown-convenient to illustrate the f application" of my invention but it-must; be understood that itl'may be attached to otherforrns er to operate efl'ectively. g a What I'claim as myjinventionis 7 1. In a'davitattachnient, the combination with the davit frame and boom, of .means arranged upon the. frame and adapted to be operated by the boom and'throu'gh the, operation of; the boom ,to effect 'a 'reactionary pull upon the'tackleropes' supporting the boat as the boom head Sw outwardly:

pnddoivnwaigdly, V p b In a ttachment; the-combination with the'da'vit frame and boom', -of alever boom head moves outboard of the perpen dicular line of support of the load.

3. In a davit attachment, the combination with the davit frame and boom, of a lever member pivoted on the frame intermediate of its length having one end secured to the tackle ropes supporting the boat, a shackle rod connecting the opposite end of said lever with the boom and adapted to swing said lever in a direction opposite to the movement of the boom as the boom swings outboard of the perpendicular line of support of the load.

4. In a davit attachment, the combination With the davit frame and boom, of a lever member pivoted on the frame intermediate of its length having one end secured to the tackle ropes supporting the boat, means for operating the boom, and a shackle rod pivotally connected at one end to said boom operating means and at the other end to said lever to effect the operation of said lever in a direction opposed to the movement of the boom outboard of the perpendicular line of support of the load.

5. In a davit attachment, the combination With the davit frame and boom, of a lever pivoted on the frame and having one end connected to the ropes for supporting the boat, and a shackle rod connecting the other L end of said lever with the boom to effect a reversal of the movement of said lever at a point intermediate of the movement of the boom.

THOMAS HENRY MARTEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, .D. G. 

